Abstract: A piezoelectric activated dither suspension system for a ring laser gyroscope has all of the transducer elements connected in parallel to simultaneously produce sustaining torque for dither motion and respond to a back component of current produced by the vibrational motion of the gyro block. The generated current, separated from drive currents from the torquer amplifier by a transformer or, in an alternative embodiment, by sensing resistors, produces the very signal used to control and sustain the oscillations. By utilizing all transducers both as torquer and pickoff elements, economies of drive efficiency, wiring simplification and circuit redundancies are achieved.

Abstract: Electro-optical apparatus for the control of the optical path length in a laser angular rate sensor. An output of a fringe detector dual photodiode and preamplifier, normally present, is processed to recover a laser intensity component present as an amplitude modulation superimposed on the phase-modulated fringe detector signal. The laser intensity component is then provided as an input to the optical path length feedback control system.

Abstract: An electronic dither compensator for a ring laser gyroscope uses a velocity pickoff to eliminate the need for a differentiator following a displacement pick off in order to get a rate signal. The dither pickoff is converted, in a voltage to frequency converter, to a pulse train which is synchronized with the pulse train of the uncompensated input from the gyro detector. An automatic gain control with an amplitude control loop is provided. The pulses from the voltage-to-frequency converter and uncompensated inputs are synchronized and summed and differenced as selected by means of logic to produce gyro output pulses free from the effects of dither rate.

Abstract: A signal processor which involves separation of the cell signals from a magnetic resonance gyro (MRG) using phase locked loops that also serve as frequency multipliers, phase shifting one cell output to maintain phase comparisons within the monotonic region of the phase detectors, PDM/Digital conversion of the MRG signals and finally microcomputer processing to obtain gyro angle to the required resolution and update rate.

Abstract: A transimpedance amplifier is connected in a positive regenerative loop with a crystal resonator. The transimpedance amplifier includes a high gain amplifier with a parallel resistor and capacitor thereacross. A virtual ground is created at the node between the resonator and the amplifier input thereby eliminating circuit sensitivity to inherent capacitive changes between the resonator and true ground. Components are chosen to maintain oscillations at series resonance and achieve insensitivity to changes in the motional resistance of the resonator.

Abstract: A phase shifter of a signal processor which involves separation of the cell signals from a magnetic resonance gyro (MRG) using phase locked loops that also serve as frequency multipliers, phase shifting one cell output to maintain phase comparisons within the monotonic region of the phase detectors, PDM/Digital conversion of the MRG signals and finally microcomputer processing to obtain gyro angle to the required resolution and update rate.

Abstract: A gyro includes piezoelectric force transducers which are oscillator driven. As the gyro undergoes angular displacement, the oscillators "follow" the instant natural frequency of the transducers and FM signals are generated at the oscillator outputs which are processed by the present invention to produce digital signals proportional to gyro angular inputs and resolved about two axes.

Abstract: A method and apparatus for phase locking the dither motions of a set of ring laser gyroscopes are shown. To prevent a variation of force from existing on a strapped-down sensor block having a plurality of ring laser gyroscopes means are provided permitting only one gyroscope to determine the frequency of oscillation of its dither suspension system. The remaining gyroscopes are slaved in both frequency and phase to the reference rather than acting independently, or locked in frequency only. The circuitry for the master and slave units have similar components, and operate substantially the same except that the signal from the variable frequency oscillator of the master unit is used as the second input to the phase detectors of the slave units rather than them using the output of their own variable frequency oscillators.

Abstract: A piezo-electric crystal vibrating in several modes controls several frequencies generated by voltage controlled oscillators simultaneously. The output of each voltage controlled oscillator is fed to a summing amplifier which drives the crystal. The output of the crystal is fed to individual phase detectors; each phase detector is also supplied with the output of a voltage controlled oscillator and generates a voltage proportional to the phase difference between the voltage controlled oscillator and the crystal output for correcting the output frequency of each oscillator.

Abstract: In a gyroscope including a rotor spinning about a spin axis, the rotor gimballed about two mutually perpendicular axes and including cross coupled closed loops operative on the two mutually perpendicular axes so as to be able to detect rates about said two axes, a feedback loop is provided to cause the gyroscope spin axis to nutate in a cone about its nominal, blind, spin axis at a controlled amplitude and at a frequency which is at least close to the natural nutation frequency of the gyro and the nutation detected and changes in the nutation amplitude or frequency used as a measure of the rate about the blind axis.

Abstract: An electrostatic motor which is well suited for an electrostatic gyro rotor spin up, spin down system which provides positive starting at any rotor position, choice of clock-wise or counter-clockwise rotation, spin up and spin down modes with automatic coast and stop modes, choice of full speed along with having zero induced rotor voltage and non-displacemental force generation is shown.